50 research outputs found

    State-of-the-Art Multihoming Protocols and Support for Android

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    Il traguardo più importante per la connettività wireless del futuro sarà sfruttare appieno le potenzialità offerte da tutte le interfacce di rete dei dispositivi mobili. Per questo motivo con ogni probabilità il multihoming sarà un requisito obbligatorio per quelle applicazioni che puntano a fornire la migliore esperienza utente nel loro utilizzo. Sinteticamente è possibile definire il multihoming come quel processo complesso per cui un end-host o un end-site ha molteplici punti di aggancio alla rete. Nella pratica, tuttavia, il multihoming si è rivelato difficile da implementare e ancor di più da ottimizzare. Ad oggi infatti, il multihoming è lontano dall’essere considerato una feature standard nel network deployment nonostante anni di ricerche e di sviluppo nel settore, poiché il relativo supporto da parte dei protocolli è quasi sempre del tutto inadeguato. Naturalmente anche per Android in quanto piattaforma mobile più usata al mondo, è di fondamentale importanza supportare il multihoming per ampliare lo spettro delle funzionalità offerte ai propri utenti. Dunque alla luce di ciò, in questa tesi espongo lo stato dell’arte del supporto al multihoming in Android mettendo a confronto diversi protocolli di rete e testando la soluzione che sembra essere in assoluto la più promettente: LISP. Esaminato lo stato dell’arte dei protocolli con supporto al multihoming e l’architettura software di LISPmob per Android, l’obiettivo operativo principale di questa ricerca è duplice: a) testare il roaming seamless tra le varie interfacce di rete di un dispositivo Android, il che è appunto uno degli obiettivi del multihoming, attraverso LISPmob; e b) effettuare un ampio numero di test al fine di ottenere attraverso dati sperimentali alcuni importanti parametri relativi alle performance di LISP per capire quanto è realistica la possibilità da parte dell’utente finale di usarlo come efficace soluzione multihoming

    Direct transition from quantum escape to phase diffusion regime in YBaCuO biepitaxial Josephson Junctions

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    Dissipation encodes interaction of a quantum system with the environment and regulates the activation regimes of a Brownian particle. We have engineered grain boundary biepitaxial YBaCuO junctions to drive a direct transition from quantum activated running state to phase diffusion regime. The cross-over to the quantum regime is tuned by the magnetic field and dissipation is encoded in a fully consistent set of junction parameters. To unravel phase dynamics in moderately damped systems is of general interest for advances in the comprehension of retrapping phenomena and in view of quantum hybrid technology

    3D Topology Transformation with Generative Adversarial Networks

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    Generation and transformation of images and videos using artificial intelligence have flourished over the past few years. Yet, there are only a few works aiming to produce creative 3D shapes, such as sculptures. Here we show a novel 3D-to-3D topology transformation method using Generative Adversarial Networks (GAN). We use a modified pix2pix GAN, which we call Vox2Vox, to transform the volumetric style of a 3D object while retaining the original object shape. In particular, we show how to transform 3D models into two new volumetric topologies - the 3D Network and the Ghirigoro. We describe how to use our approach to construct customized 3D representations. We believe that the generated 3D shapes are novel and inspirational. Finally, we compare the results between our approach and a baseline algorithm that directly convert the 3D shapes, without using our GAN

    Coherent transport in extremely underdoped Nd1.2Ba1.8Cu3Oz nanostructures

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    Proximity-effect and resistance magneto-fluctuations measurements in submicron Nd1.2Ba1.8Cu3Oz (NBCO) nano-loops are reported to investigate coherent charge transport in the non-superconducting state. We find an unexpected inhibition of cooper pair transport, and a destruction of the induced superconductivity, by lowering the temperature from 6K to 250mK. This effect is accompanied by a significant change in the conductance-voltage characteristics and in the zero bias conductance response to the magnetic field pointing to the activation of a strong pair breaking mechanism at lower temperature. The data are discussed in the framework of mesoscopic effects specific to superconducting nanostructures, proximity effect and high temperature superconductivity.Comment: to appear on new journal of Physic

    Origin of interface magnetism in BiMnO3/SrTiO3 and LaAlO3/SrTiO3 heterostructures

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    Possible ferromagnetism induced in otherwise non-magnetic materials has been motivating intense research in complex oxide heterostructures. Here we show that a confined magnetism is realized at the interface between SrTiO3 and two insulating polar oxides, BiMnO3 and LaAlO3. By using polarization dependent x-ray absorption spectroscopy, we find that in both cases the magnetic order is stabilized by a negative exchange interaction between the electrons transferred to the interface and local magnetic moments. These local magnetic moments are associated to Ti3+ ions at the interface itself for LaAlO3/SrTiO3 and to Mn3+ ions in the overlayer for BiMnO3/SrTiO3. In LaAlO3/SrTiO3 the induced magnetic moments are quenched by annealing in oxygen, suggesting a decisive role of oxygen vacancies in the stabilization of interfacial magnetism.Comment: 5 pages, 4 figure

    Cardiovascular disease risk in liver transplant recipients transplanted due to chronic viral hepatitis

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    Background: Cardiovascular disease (CVD) is a major cause of morbidity and mortality after liver transplantation, mostly in patients transplanted for nonalcoholic steatohepatitis, obesity and diabetes. Few data exist on cardiovascular diseases among patients transplanted for viral hepatitis. Objective: Our aim is to clarify the cardiovascular risk and subclinical vascular damage among liver transplant recipients for chronic viral hepatitis (i.e. hepatits C virus, hepatis B virus and hepatitis D virus infection). Methods: Adult patients (age ≥ 18 years) with orthotopic liver transplants (OLT) due to viral hepatitis who signed informed consent, and were admitted for a routine follow-up between June 2019 and September 2020 at the Infectious Disease outpatient clinic of the University of Campania Luigi Vanvitelli, Naples, Italy, were prospectively enrolled. An estimation of cardiovascular risk was assessed using three main risk charts, echocolor-Doppler of epiaortic vessels was performed to assess subclinical Intima-Media changes. Results: A total of 161 patients were evaluated; of these 15 were excluded because not affected by viral hepatitis. 146 patients were considered. 83 patients (56.8%) were considered at high cardiovascular risk according to Framingham, 54 patients (36.9%) to American Heart Association Arteriosclerotic Cardiovascular Disease (ASCVD) score and 19 (13.0%) to Heart Score. Only 8 patients (5.4%) showed a normal carotid ultrasound, while 52 patients (35.6%) had a carotid artery Intima-Media Thickness (IMT) and 86 (58.9%) an atherosclerotic plaque. Conclusions: Liver transplant recipients for virus-related associated liver disease are, in light of the high percentage of carotid lesions, at high risk of CVD. Risk charts compared to subclinical carotid lesions which represent damage already established and a real localization of the disease, seem to underestimate the cardiovascular risk. A chronic inflammatory status, could play a key role. It's important to raise the awareness of cardiovascular risk in liver transplant patients to prevent cardiovascular diseases and improve the timing of early diagnosis of premature vascular lesions

    HDV can constrain HBV genetic evolution in hbsag: Implications for the identification of innovative pharmacological targets

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    Chronic HBV + HDV infection is associated with greater risk of liver fibrosis, earlier hepatic decompensation, and liver cirrhosis hepatocellular carcinoma compared to HBV mono-infection. However, to-date no direct anti-HDV drugs are available in clinical practice. Here, we identified conserved and variable regions in HBsAg and HDAg domains in HBV + HDV infection, a critical finding for the design of innovative therapeutic agents. The extent of amino-acid variability was measured by Shannon-Entropy (Sn) in HBsAg genotype-D sequences from 31 HBV + HDV infected and 62 HBV mono-infected patients (comparable for demographics and virological-parameters), and in 47 HDAg genotype-1 sequences. Positions with Sn = 0 were defined as conserved. The percentage of conserved HBsAg-positions was significantly higher in HBV + HDV infection than HBV mono-infection (p = 0.001). Results were confirmed after stratification for HBeAg-status and patients’ age. A Sn = 0 at specific positions in the C-terminus HBsAg were correlated with higher HDV-RNA, suggesting that conservation of these positions can preserve HDV-fitness. Conversely, HDAg was characterized by a lower percentage of conserved-residues than HBsAg (p < 0.001), indicating higher functional plasticity. Furthermore, specific HDAg-mutations were significantly correlated with higher HDV-RNA, suggesting a role in conferring HDV replicative-advantage. Among HDAg-domains, only the virus-assembly signal exhibited a high genetic conservation (75% of conserved-residues). In conclusion, HDV can constrain HBsAg genetic evolution to preserve its fitness. The identification of conserved regions in HDAg poses the basis for designing innovative targets against HDV-infection

    State-of-the-art multihoming solutions for Android: A quantitative evaluation and experience report

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    The technical challenges associated with multihoming management in mobile systems and applications have attracted relevant research activities, as demonstrated by the wide related literature of the recent years. However, only very recently some multihoming solutions and techniques have started to be applied in industrially-relevant platforms and cases, often in a limited and very controlled way. This paper has the specific and focused objective of reporting a fresh state-of-the-art overview of the maturity of multihoming solutions for Android and to describe our practical experience of multihoming configuration and evaluation over off-the-shelf Android devices. In particular, we report the experience made while considering the relevant Locator/Identifier Separation Protocol (LISP) and especially LISPmob support solutions, by i) showing how to efficiently configure LISPmob on non-rooted Android devices; and ii) thoroughly analyzing its supported features towards the abstraction of seamless mobility. In addition, the paper includes a qualitative and quantitative comparison of different multihoming support approaches, as well as original experimental results about the performance of LISPmob over Android terminals

    On how to efficiently implement deep learning algorithms on PYNQ platform

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    Deep Learning algorithms are gaining momentum as main components in a large number of fields, from computer vision and robotics to finance and biotechnology. At the same time, the use of Field Programmable Gate Arrays (FPGAS) for data-intensive applications is increasingly widespread thanks to the possibility to customize hardware accelerators and achieve high-performance implementations with low energy consumption. Moreover, FPGAS have demonstrated to be a viable alternative to GPUS in embedded systems applications, where the benefits of the reconfigurability properties make the system more robust, capable to face the system failures and to respect the constraints of the embedded devices. In this work, we present a framework to efficiently implement Deep Learning algorithms by exploiting the PYNQ platform, recently released by Xilinx. The case study application is tested on PYNQ-Z1 board, commonly used in embedded system applications
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